{ESCALATE_SOCKET_ENV_VAR} is not a valid file descriptor: {c

Error message

{ESCALATE_SOCKET_ENV_VAR} is not a valid file descriptor: {client_fd}

What it means

Error "{ESCALATE_SOCKET_ENV_VAR} is not a valid file descriptor: {client_fd}" thrown in openai/codex.

Source

Thrown at codex-rs/shell-escalation/src/unix/escalate_client.rs:23

use anyhow::Context as _;
use codex_utils_absolute_path::AbsolutePathBuf;

use crate::unix::escalate_protocol::ESCALATE_SOCKET_ENV_VAR;
use crate::unix::escalate_protocol::EXEC_WRAPPER_ENV_VAR;
use crate::unix::escalate_protocol::EscalateAction;
use crate::unix::escalate_protocol::EscalateRequest;
use crate::unix::escalate_protocol::EscalateResponse;
use crate::unix::escalate_protocol::SuperExecMessage;
use crate::unix::escalate_protocol::SuperExecResult;
use crate::unix::socket::AsyncDatagramSocket;
use crate::unix::socket::AsyncSocket;

fn get_escalate_client() -> anyhow::Result<AsyncDatagramSocket> {
    // TODO: we should defensively require only calling this once, since AsyncSocket will take ownership of the fd.
    let client_fd = std::env::var(ESCALATE_SOCKET_ENV_VAR)?.parse::<i32>()?;
    if client_fd < 0 {
        return Err(anyhow::anyhow!(
            "{ESCALATE_SOCKET_ENV_VAR} is not a valid file descriptor: {client_fd}"
        ));
    }
    Ok(unsafe { AsyncDatagramSocket::from_raw_fd(client_fd) }?)
}

fn duplicate_fd_for_transfer(fd: impl AsFd, name: &str) -> anyhow::Result<OwnedFd> {
    fd.as_fd()
        .try_clone_to_owned()
        .with_context(|| format!("failed to duplicate {name} for escalation transfer"))
}

pub async fn run_shell_escalation_execve_wrapper(
    file: String,
    argv: Vec<String>,
) -> anyhow::Result<i32> {
    let handshake_client = get_escalate_client()?;
    let (server, client) = AsyncSocket::pair()?;

View on GitHub (pinned to 339751715c)

When it happens

Trigger: Thrown at codex-rs/shell-escalation/src/unix/escalate_client.rs:23 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of openai/codex@339751715c (2026-08-25). Data as JSON: /api/errors/f9708293f8fd0392. Report an issue: GitHub.